Iso-tridecanolalkoxylates in block form as low-foam or antifoaming surfactants

ABSTRACT

Isotridecanol block alkoxylates I ##STR1## where R is isotridecyl, 
     m is 2 when n is 3 or 4, or 
     m is 3 or 4 when n is 2, and 
     x and y are independently of each other from 1 to 20, 
     subject to the proviso that x is not less than y when m=2 and n=3 or 4, 
     are useful as low-foam or foam-suppressing surfactants, especially in detergent and cleaner formulations and for chemical-technical applications.

DESCRIPTION

The present invention relates to the use of isotridecanol blockalkoxylates having an ethylene oxide block and a propylene oxide orbutylene oxide block as low-foam or foam-suppressing surfactants,especially in detergent and cleaner formulations and forchemical-technical applications. The present invention further relatesto detergent and cleaner formulations comprising these isotridecanolblock alkoxylates.

Nonionic surfactants based on alkoxylates and block alkoxylates oflong-chain alcohols of natural or synthetic origin are essentialconstituents of customary detergent and cleaner formulations. Similarly,block alkoxylates of isotridecanol are known in principle.

For instance, DE-A 22 09 559 (1) describes an adduct of 2 mol ofethylene oxide and 4 mol of propylene oxide with isotridecanol as acomponent in agents for foam control, for example for use in polymerdispersions and in the coatings, paper and food industries.

Furthermore, WO-A 92/14808 (2) recommends the use of a mixture of twosimilar alkoxylated long-chain alcohols, the long-chain alcohols eachhaving first been reacted with ethylene oxide and then with propyleneoxide, as foam-suppressing surfactant in cleaners for mechanicalcleaning processes and in rinse aids for mechanical ware cleaning. Thelong-chain alcohols mentioned as candidates for alkoxylation includeisotridecanol. In the block alkoxylates disclosed in (2), the degree ofpropoxylation is always higher than the degree of ethoxylation; forinstance, Example 1 of (2) describes an adduct of 3.5 mol of ethyleneoxide and 5.5 mol of propylene oxide with a C₁₃ /C₁₅ oxo alcohol.

Similarly, derivatives of isotridecanol block alkoxylates are known inthe art. For instance, GB-A 2 196 632 (3) describes isotridecanolalkoxylates having a propylene oxide block, an ethylene oxide block anda phosphoric ester end group. These surface-active agents arerecommended for use as wetting agents in the pretreatment of textilematerials in the textile-making industry. EP-A 003 183 (4) disclosesblock alkoxylates, of isotridecanol among others, having a propyleneoxide block, an ethylene oxide block and a hydrophilic end group such assulfate, sulfonate, phosphate or carboxylate. These surface-activeagents are used in petroleum production.

However, known surfactants based on alkoxylates of long-chain alcoholsin the field of detergents and cleaners and in the field ofchemical-technical applications have a number of disadvantages. Forinstance, particularly physical and application properties such assurface tension, wetting power and foam behavior are in need ofimprovement. Also, the known agents usually have a relatively highecotoxicological hazard potential, especially with respect to aquaticorganisms.

It is an object of the present invention to provide surfactants for thedetergent and cleaner sector and for chemical-technical applicationswithout the aforementioned disadvantages.

We have found that this object is achieved by the use of isotridecanolblock alkoxylates of the general formula I ##STR2## where R isisotridecyl,

m is 2 when n is 3 or 4, or

m is 3 or 4 when n is 2, and

x and y are independently of each other from 1 to 20,

subject to the proviso that x is not less than y when m=2/n=3 or 4,

as low-foam or foam-suppressing surfactant.

The isotridecanol (isotridecyl alcohol) is of synthetic origin in thatit is produced by oligomerization of suitable lower olefins andsubsequent oxo reaction (hydroformylation). For instance, isobutylene,1-butylene, 2-butylene or mixtures thereof can be catalyticallytrimerized, propylene catalytically tetramerized or 2-methyl-1-pentenecatalytically dimerized. The C₁₂ olefins thus obtainable are thenconverted to the homologous C₁₃ alcohol, for example by means of CO andH₂ over a suitable catalyst.

The bulk of the isotridecanol comprises primary C₁₃ alkanols having atleast 3, especially 4, branches (alkyl side chains). In general they aretetramethylnonanols, for example 2,4,6,8-tetramethyl-1-nonanol or3,4,6,8-tetramethyl-1-nonanol. Ethyldimethylnonanols such as5-ethyl-4,7-dimethyl-l-nonanol can also be present.

However, the underlying alcohol component need not be just pureisotridecanol; homologous mixtures of branched C₁₁ to C₁₄ alkanolscomprising isotridecanol as main component are also suitable. Suchhomologous mixtures are formed under certain conditions in the course ofthe above-described oligomerization of lower olefins and subsequent oxoreaction. A typical composition of such a mixture is as follows:

branched C₁₁ alkanol (isoundecanol) 2-15% by weight

branched C₁₂ alkanol (isododecanol) 15-35% by weight

isotridecanol 55-75% by weight

branched C₁₄ alkanol (isotetradecanol) 1-10% by weight.

The isotridecanol used in the present invention must be distinguishedfrom the "C₁₃ /C₁₅ oxo alcohols", which are mixtures of correspondinglinear olefins, i.e. α-dodecene and α-tetradecene, which have beenhydroformylated. The resulting C₁₃ and C₁₅ alkanols are linear or havenot more than one side chain.

The degrees of alkoxylation x and y, which in general are averages,since the alkylene oxide units are usually present in a randomdistribution with a frequency maximum, are preferably independently ofeach other from 1.5 to 12. By means of specific alkoxylation catalysts,for example modified bentonites or hydrotalcites, as described in WO-A95/04024, the random distribution can be narrowed to such an extent thatnarrow range alkoxylates are obtained.

The disclosed isotridecanol block alkoxylates I are either ethyleneoxide-propylene oxide or -butylene oxide adducts of the formula Ia##STR3## or propylene oxide- or butylene oxide-ethylene oxide adducts ofthe formula Ib ##STR4## If m or n is equal to 3 or 4, the preference isfor 3 (propylene oxide block).

The ratio between x and y, which plays a part in determining the balancebetween hydrophilic and hydrophobic moieties, is not less than 1 in theadducts Ia; preferably, the ratio of x to y is within the range from 1:1to 4:1, especially within the range from 1.5:1 to 3:1.

The ratio of x and y in adducts Ib is somewhat less critical and isgenerally within the range from 1:3 to 3:1, preferably within the rangefrom 1:1.5 to 3:1.

The disclosed isotridecanol block alkoxylates I are preferably used asnonionic surfactants in detergent and cleaner formulations and insurfactant-including formulations for chemical-technical applications,for example for cleaning processes in industry and the home as well asfor textile washing or for cleaning processes in the food sector such asthe cleaning of beverage bottles or of containers or equipment in thefood-processing industry or in ware cleaners. Of particular interesthere is the cleaning of hard surfaces composed for example of glass,ceramic, paint, plastic or metal. The surfactants I are also used intechnical cleaners and in cleaning processes in the metal-processingindustry.

The surfactants I can also be used with advantage for a multiplicity ofother chemical-technical processes, for instance generally in themetal-processing industry, for example in

cooling lubricants,

hardening media,

hydraulic oil emulsions,

polishing pastes,

mold release agents,

drawing media,

pickling media,

metal cleaners,

metal driers.

Here the surfactants I can be specifically used with advantage in thoseprocesses where high thermal stability is required.

The surfactants I can further be used in the making and processing oftextiles. The use of surfactants in the making and processing oftextiles is very wide, extending in the main to the fields of

pretreatment agents for fibers,

production of rayon fibers,

spin finishes and textile lubricants,

dyeing assistants,

softeners,

water repellents,

printing assistants,

antistats,

flocking and coating compositions.

The surfactants I can further be used in the leather, paper, printing,electroplating and photographic industries. Important fields ofapplication here are coatings, pigments and printing inks. Surfactantsare used in these applications not only in aqueous but also innonaqueous systems. In nonaqueous systems, they are chiefly effective asdispersants, antisettling agents or flow control agents. In addition,surfactants make it possible to produce high-solids systems. Surfactantshave a larger proportion in aqueous systems, in which they not onlyserve to stabilize the polymeric binder dispersions prepared by emulsionaddition or condensation polymerization but also to assist thedispersion of organic and inorganic pigments frequently present. Inaddition, they improve the adhesion properties of these coatings.

The surfactants I can also be used in water treatment, for example inwastewater cleanup.

The surfactants I can further be used in crop protection formulations.

The compounds I can further be used as surfactants or emulsifiers in theplastics-making and plastics-processing industry. The main fields ofapplication in plastics making and processing are

production of polymer dispersions,

production of bead polymers,

production of foam plastics,

use of surface-active mold release agents,

production of microcapsules,

improving the adhesion between fillers and plastics,

additions to polymer dispersions to achieve special effects such asfoamability, filler compatibility or wetting power,

emulsifiers for nonaqueous systems,

coloring of plastics,

antistatic finishing of plastics,

adhesives.

The present invention likewise provides detergent and cleanerformulations which, as well as the customary constituents, include from0.1 to 40% by weight, in particular from 5 to 30% by weight, especiallyfrom 10 to 25% by weight, based on the total amount of the formulation,of at least one isotridecanol block alkoxylate I as surfactant. Inaddition, these formulations may include further nonionic surfactants,but also cationic, anionic and/or amphoteric surfactants. The customaryconstituents of detergent and cleaner formulations are known to thoseskilled in the art and therefore need not be discussed here any further.

The disclosed isotridecanol block alkoxylates I usually exhibit aremarkably low interfacial tension, especially with respect to apolaroils such as engine oils (important for application in technicalcleaners) or fatty oils such as olive oil (important for application inmanual ware cleaners), which is very highly correlated with a highfat-dissolving power, is effective to reduce the surface tension andresults in a very low critical micelle concentration. They generallyexhibit good wetting power in respect of hard surfaces and very goodwetting power on textile surfaces. In the wash they usually produceminimal foam, which makes them suitable for textile detergents,especially washing powders. Even in mechanical and manual cleaningprocesses they generally generate little foam, usually actfoam-suppressingly and are usually effective in bringing about rapidfoam disintegration.

The disclosed isotridecanol block alkoxylates I are readilybiodegradable and toxicologically substantially safe; more particularly,their aquatic toxicity is significantly lower than that of comparablecommercial products.

EXAMPLES

The following isotridecanol block alkoxylates were prepared and testedin respect of their application properties:

isotridecyl-O-(C₂ H₄ O)_(x) --(C₃ H₆ O)_(y) --H

Examples No. 1-12

    ______________________________________                                                                              Foam                                         Cloud Surface suppression                                                  Example   point (cp) tension behavior                                         No. x y [° C.] [mN/m] [rpm]                                          ______________________________________                                        1       6.0     3.0    46.5    28.3   79                                        2 6.3 3.1 47.0 29.1 71                                                        3 6.0 4.0 42.0 29.3 72                                                        4 4.0 3.0 38.5 28.9 73                                                        5 4.0 4.0 35.0 29.4 74                                                        6 5.0 4.0 38.5 29.3 72                                                        7 5.0 3.0 42.0 29.0 68                                                        8 9.0 3.0 54.0 28.5 64                                                        9 12.0 3.0 60.5 30.7 33                                                       10  6.0 4.5 40.0 28.9 75                                                      11  9.0 4.5 48.0 28.9 80                                                      12  12.0 4.5 54.0 30.3 65                                                   ______________________________________                                    

isotridecyl-O-(C₃ H₆ O)_(x) --(C₂ H₄ O)_(y) --H

Examples No. 13-19

    ______________________________________                                                                              Foam                                         Cloud Surface suppression                                                  Example   point (cp) tension behavior                                         No. x y [° C.] [mN/m] [rpm]                                          ______________________________________                                        13      4.0     1.7    35.0    28.7   108                                       14 4.5 1.5 30.5 28.6 107                                                      15 4.5 3.0 45.5 28.5 92                                                       16 4.5 4.5 54.5 28.7 63                                                       17 3.0 1.5 29.0 27.3 106                                                      18 3.0 3.0 45.5 27.8 93                                                       19 3.0 4.5 56.5 27.9 59                                                     ______________________________________                                    

The cloud point was determined in butyldiglycol by the method of DIN 53917. This involves determining the temperature above which the solutionturns cloudy and is thus present as a mixture of two liquid phases. Thelower the cloud temperature, the lower the foaming tendency.

The surface tension was determined in accordance with DIN 53 924 bymeasuring the force in mN/m required to pull a plate or a horizontallysuspended ring from the liquid surface.

The foam suppression behavior in the dishwasher was tested by means ofthe "egg test". In this test, magnetic induction measurement is used tocount the number of revolutions of a spraying arm in a domesticdishwasher with the aid of a counter. Foaming, which occurs inparticular in the presence of proteins, reduces the speed of the arm.Because of the reduced thrust, the speed of the arm is thus a measure ofthe suitability of surfactants for use in high-agitation cleaningequipment. To test the foam suppression behavior, an egg is added to thewash liquor. The test time is 12 min, and the average number ofrevolutions per minute is calculated from the total number ofrevolutions. The wash is started at room temperature, but after about 10min the temperature of the wash liquor is 60° C.

The isotridecyl radical used in Examples 1 to 19 represents the isomericmixture of branched C₁₃ alkanols produced in the trimerization of amixture of 1-butylene and 2-butylene and subsequent hydroformylation.

The substances of Examples 1 to 19 were prepared by the followingmethods:

Example 1

An autoclave was charged initially with 200 g of isotridecanol(corresponding to 1.0 mol) together with 0.2 g of potassium hydroxide asalkoxylation catalyst. 264 g of ethylene oxide gas (corresponding to 6.0mol) were continuously introduced at from 110 to 120° C. To complete thereaction, the batch was subsequently stirred at the same temperature for1 h. Then 174 g of propylene oxide (corresponding to 3.0 mol) were addedcontinuously at from 130 to 140° C. The batch was subsequently allowedto react at that temperature for 2 h. 638 g were obtained of thesubstance of Example 1. The substances of Examples 2 to 12 were preparedin a similar manner.

Example 13

An autoclave was charged initially with 200 g of isotridecanol(corresponding to 1.0 mol) together with 0.2 g of potassium hydroxide asalkoxylation catalyst. 232 g of propylene oxide gas (corresponding to4.0 mol) were continuously introduced at from 130 to 140° C. To completethe reaction, the batch was subsequently stirred at the same temperaturefor 1 h. Then 75 g of ethylene oxide (corresponding to 1.7 mol) wereadded continuously at from 110 to 120° C. The batch was subsequentlyallowed to react at that temperature for 2 h. 507 g were obtained of thesubstance of Example 13. The substances of Examples 14 to 19 wereprepared in a similar manner.

We claim:
 1. A process for producing low-foam or foam-suppressingsurfactant-including formulations, which comprises including in theseformulations at least one isotridecanol block alkoxylate I of thegeneral formula I:

    R--O--(C.sub.m H.sub.2m O).sub.x --(C.sub.n H.sub.2n O).sub.y --H(I)

wherein R is isotridecyl which is mainly based on primary C₁₃ alkanolshaving at least 3 branches, m and n are independently 2, 3 or 4, and mis 2 when n is 3 or 4, or m is 3 or 4 when n is 2, and x and y areindependently of each other from 1 to 20, with the proviso that x is notless than y when m=2, and n=3 or
 4. 2. The process as claimed in claim1, wherein x and y are independently of each other from 1.5 to
 12. 3.The process as claimed in claim 1, wherein x and y are in a ratio offrom 1:1 to 4:1 when m=2, n=3 or
 4. 4. The process as claimed in claim1, wherein x and y are in a ratio of from 1:3 to 3:1 wherein m=3 or 4,and n=2.
 5. The process as claimed in claim 1, wherein R represents anisomeric mixture of branched C₁₃ alkanols produced in the trimerizationof a mixture of 1-butylene and 2-butylene and subsequenthydroformulation.
 6. A laundry detergent and cleaner formulationcomprising from 0.1 to 40% by weight, based on the total amount of theformulation, of at least one isotridecanol block alkoxylate Irepresented by formula (I) as surfactant:

    R--O--(C.sub.m H.sub.2m O).sub.x --(C.sub.n H.sub.2n O).sub.y --H(I)

wherein R is isotridecyl which is mainly based on primary C₁₃ alkanolshaving at least 3 branches, m and n are independently 2, 3 or 4, and mis 2 when n is 3 or 4, or m is 3 or 4 when n is 2, and x and y areindependently of each other from 1 to 20, with the proviso that x is notless than y when m=2, and n=3 or
 4. 7. The laundry detergent and cleanerformulation of claim 6, wherein R represents an isomeric mixture ofbranched C₁₃ alkanols produced in the trimerization of a mixture of1-butylene and 2-butylene and subsequent hydroformulation.
 8. Thelaundry detergent and cleaner formulation in claim 6, wherein x and yare independently of each other from 1.5 to
 12. 9. The laundry detergentand cleaner formulation in claim 6, wherein x and y are in a ratio offrom 1:1 to 4:1 when m=2, and n=3 or
 4. 10. The laundry detergent andcleaner formulation in claim 6, wherein x and y are in a ratio of from1:3 to 3:1 when m=3 or
 4. and n=2.